The present invention generally relates to a collimator and, in particular, relates to one such collimator adapted to directly couple to an optical fiber.
The use of optical fibers has been growing in recent years. However, although the usefulness of optical fibers has been amply demonstrated, much work remains to derive the full benefits thereof. For example, one area of difficulty is the physical coupling of an optical fiber to a device or mechanism interacting therewith. Currently, such a coupling is difficult to accomplish and frequently requires elaborate methods and/or devices to ensure the accurate alignment of the optical fibers. One reason for these requisites is that light emanating from an end of an optical fiber immediately begins to disperse. Thus, to promote maximum signal transfer of an optical signal from an optical fiber, a collimating lens, usually a spherical bead lens, is frequently provided, usually at the end of each optical fiber. Likewise, when a light beam is to be coupled into an optical fiber the light beam must be finely focused onto the optical fibers end to avoid considerable light signal losses. The attachment of the fiber end to a collimating lens is currently time consuming to accomplish. As a consequence, the labor costs and expense relating to just the use of a discrete collimating lens often hampers the complete implementation of optical fibers in devices and systems that would clearly benefit therefrom.
One example of a device that would clearly benefit from a less costly optical fiber interconnection is a liquid crystal optical switching device.
Typical of early crystal optical switching device designs are those described and discussed in U.S. Pat. No. 4,201,422 issued on May 6, 1980 to McMahon et al, U.S. Pat. No. 4,278,327 issued on July 14, 1981 to McMahon et al and U.S. Pat. No. 4,385,799 issued on May 31, 1983 to Soref.
More recently, improved liquid crystal optical switching device designs have been described and discussed in co-pending U.S. patent application Ser. Nos: 795,138; 795,148, now U.S. Pat. No. 4,749,258; 795,149, now U.S. Pat. No. 4,711,529; 795,150; 795,151, now U.S. Pat. No. 4,737,019; 795,152, now U.S. Pat. No. 4,720,174, 795,154; 795,155, now U.S. Pat. No. 4,720,171; 795,156; 795,157; and 795,296 all filed on Nov. 5, 1985 and assigned to the assignee hereof. These applications are deemed incorporated herein by reference.
Almost without exception the devices discussed in the above referenced patents and patent applications require at least one collimating lens. In fact, one particular device that overcomes the usual surface mounting complexities, specifically U.S. patent application Ser. No. 795,156 entitled LIQUID CRYSTAL OPTICAL SWITCHING DEVICE, nevertheless, requires, in one embodiment thereof, the use of a spherical collimating lens that is positioned within a blind opening adapted to receive an optical fiber.
Consequently, a collimator, particularly adapted for use with optical fibers as well as devices utilizing optical fibers, that is both inexpensive and readily interconnected with an optical fiber is needed to further the utilization of optical fibers.